1. Industrial Field
The present invention relates to a manufacturing method of a liquid crystal display panel which is used in liquid crystal display, liquid crystal shutter, etc. and to a cleaning apparatus which is used in manufacturing the liquid crystal display panel.
2. Prior Art
A conventional liquid crystal display panel is manufactured by the steps of forming and hardening an oriented film, after forming electrodes, etc. on a surface of a glass substrate; performing either a wet cleaning by wetting, cleaning, dewatering and drying using pure water, isopropyl alcohol, etc. or a dry cleaning by blowing with nitrogen gas, dry air, etc. to remove foreign matter stuck to the surface of the substrate due to rubbing treatment, after rubbing the surface of the oriented film using a cloth of nylon, rayon or the like and giving an orientation to the film; and causing two such substrates to face each other and charging a liquid crystal between the two substrates.
The Japanese Laid-Open Patent Publication (unexamined) Hei 6-235893 discloses a method for preventing an occurrence of irregular cleaning by supporting a rubbed substrate in a steam tank before performing the wet cleaning after the rubbing treatment.
In the dry cleaning after the rubbing treatment in the conventional manufacturing process of the liquid crystal display panel, a problem exists in that the foreign matter or stain stuck to the surface of the substrate at the time of rubbing is not sufficiently removed, and in the wet cleaning, a problem exists in that irregular orientation or spot occurs on the surface of the substrate at the time when water or cleaning agent strikes on the surface of the substrate due to a difference in striking pressure. Moreover, at the time of washing the foreign matter on the substrate by water or cleaning agent, another problem exists in that the irregular orientation or spot occurs due to the rubbing of the surface of the oriented film before wetting completely the substrate.
In the method disclosed in the mentioned Japanese Laid-Open Patent Publication (unexamined) Hei 6-235893, since it is necessary for the substrate to be supported in the steam tank, it is difficult to apply such a method to the process of treating continuously one substrate after another.